The only dated entry in this notebook is from March 1902. All entries are by Edison. The book contains notes and drawings regarding several experiments that deal mainly with electricity, matter, and electromagnetic radiation. Among the entries are items pertaining to x- rays, etheric force and \"xyz rays,\"" and electrochemical recording apparatus. Also included is material relating to an organic liquid battery and the production of battery jars. The book contains 288 numbered pages; many pages are blank."